Spark falls, BioMarin gains on hemophilia A data at ASH

Spark Therapeutics Inc. (NASDAQ:ONCE) fell $25.66 (35%) to $47.72 and BioMarin Pharmaceutical Inc. (NASDAQ:BMRN) gained $6.12 to $88.11 on Monday after each company reported additional Phase I/II data on Factor VIII activity levels for their respective gene therapies to treat hemophilia A. The moves translate to a loss in market cap of almost $950 million for Spark and a gain of over $1 billion in market cap for BioMarin.

Both companies presented their findings at the American Society of Hematology meeting in Atlanta (see BioCentury, Dec. 8)...